[GCM] Extracting GCMConnectionObserver from GCMAppHandler

components/gcm_driver/gcm_driver.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/gcm_driver/gcm_driver.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
@@ skipping 167 matching lines @@
 
   // Ask the handlers whether they know how to handle it.
   for (iter = app_handlers_.begin(); iter != app_handlers_.end(); ++iter) {
     if (iter->second->CanHandle(app_id))
       return iter->second;
   }
 
   return &default_app_handler_;
 }
 
+void GCMDriver::AddConnectionObserver(GCMConnectionObserver* observer) {
+}

[jianli, 2014/08/27 23:34:17]

Please comment that connection observing is only supported in desktop version.

[fgorski, 2014/08/27 23:51:45]

Done. Made abstract in GCMDriver and moved empty methods to GCMDriverAndroid

+
+void GCMDriver::RemoveConnectionObserver(GCMConnectionObserver* observer) {
+}
+
 bool GCMDriver::HasRegisterCallback(const std::string& app_id) {
   return register_callbacks_.find(app_id) != register_callbacks_.end();
 }
 
 void GCMDriver::ClearCallbacks() {
   register_callbacks_.clear();
   unregister_callbacks_.clear();
   send_callbacks_.clear();
 }
 
 bool GCMDriver::IsAsyncOperationPending(const std::string& app_id) const {
   return register_callbacks_.find(app_id) != register_callbacks_.end() ||
          unregister_callbacks_.find(app_id) != unregister_callbacks_.end();
 }
 
 }  // namespace gcm